1. Field of the Invention
The invention relates to a self-propelled construction machine, in particular road milling machine, recycler or stabiliser, with a machine frame and an operating mechanism, wherein the operating mechanism comprises an operating drum and a drum housing surrounding the operating drum.
2. Description of the Prior Art
With the known road milling machines, the road surface can be milled true to contour and evenly. The known road milling machines have a milling mechanism, which comprises a milling drum for milling off the material. With a rear loader road milling machine, the milled material is fed to the following truck over the rear of the milling machine.
The so-called stabilisers or recyclers should be differentiated from road milling machines; by addition of binding agents to unstable ground, for example loose soil (stabiliser) or a damaged roadway (recycler), these produce a stable base that is suitable for later overlaying with a roadway.
Road milling machines and stabilisers or recyclers have in common an operating mechanism with an operating drum and a drum housing surrounding the operating drum, that is closed by at least one sealing element, that is also described as stripping element, located behind the operating drum when seen in the operating direction. Apart from the rear sealing element, road milling machines have further a sealing element, also described as hold-down device, located in front of the milling drum. In addition to the hold-down device and the stripper, road milling machines comprise a right and left edge protector extending in the operating direction, which seal the drum housing laterally.
In practice, all sealing elements basically confront the problem that the sealing element can strike obstacles in uneven areas. The sealing element must therefore be adjustable in height. This problem is encountered particularly with front and rear sealing elements extending transverse to the operating direction. The problem of tilting is encountered, especially with the rear sealing element, since the rear sealing element is employed in the operating direction and is generally fitted with disc-shaped hard metal elements at the lower edge. This problem is made still worse with the rear sealing element by the fact that this sealing element is generally subjected to a pressure.
The road milling machine with a front hold-down device and a rear stripper element is known, for example, from EP 2 050 875 A2. The road milling machine has a tracking member for adjusting the height of the hold-down device, with which the hold-down device is connected by means of a control lever to an articulated joint so that, when the tracking member strikes an obstacle, the tracking member is raised.
U.S. Pat. No. 4,723,867A describes a road milling machine, the drum housing of which has a front and a rear sealing element. Both sealing elements can be adjusted in height, so that the milling drum is accessible.